8. CLONIDINE
α ADRENOCEPTORS IN
MEDULLA OF BRAIN---Sensitizes
vasomotor centers to Inhib by
baroreflexes
RED. SYMPATHETIC AND INC.
PARASYMPATHETIC TONE
Nonadrenoceptor site----IMIDAZOLE
RECEPTOR
9. ACTIONS
I/V---BRIEF INC IN BLOOD
PRESSURE( PARTIAL α AGONIST)
followed by MORE PROLONGED
HYPOTENTION
DEC. CARDIAC RATE AND C.O
RELAXATION OF CAPACITANCE
VESSELS---DEC IN PVR
10. TOXICITY
SEDATION
DRY MOUTH
MENTAL DEPRESSION----WITHDRAW
WITHDRAWAL AFTER PROTRACTED
USE:
LIFE THREATENING HYPOTENSIVE
CRISIS
Nervousness, tachycardia, headache &
sweating---omitting 1 or 2 doses of drug
11. DRUG INTERACTIONS
TCA MAY BLOCK THE ANTI
HYPOTENSIVE EFFECT
NSAIDS MAY ENHANCE THE
ANTIPOTENSIVE EFFECT
13. GANGLION BLOCKING
AGENTS
MOA
COMPETITIVELY BLOCK NICOTINIC
CHOLINOCEPTORS ON POST
GANGLIONIC NEURONS IN
BOTH SYMPATHETIC &
PARASYMPATHETIC OUTFLOW
MAY DIRECTLY BLOCK
NICOTINIC Ach channel
14. TO NAME A FEW..
HEXAMETHONIUM
MECAMYALINE
TRIMETHAPHAN
20. THESE BLOCK NEURONAL
UPTAKE OR DISPLACE
AMINES FROM NERVE
TERMINALS
COCAINE
AMPHETAMINE
TCA
PHENOTHIAZINES
PHENOXYBENZAMINE
21. RESERPINE
MOA
Blocks the ability of aminergic
transmitter vesicles to take up and store
biological amines----interfere VMAT
-> DEPLETION OF
NE, DOPAMINE & SEROTININ
BOTH IN CENTRAL AND PERIPHERAL
NERVOUS SYSTEM
CROMAFFIN GRANULES OF AD.
MEDULLA ARE ALSO DEPLETED
22. TOXICITY
LOW DOSES—LITTLE POSTURAL
HYPOTENSION
HIGH DOSES–
SEDATION, LASSITUDE, NIGHTMARE
S, SEVERE MENTAL DEPRESSION—
occasionally with low doses too
EXTRAPYRAMIDAL EFFECTS due to low
dopamine in CS.
GIT MILD DIARREHA, GIT
CRAMPS, INCREASED GASTRIC ACID
SECRETION
CONTRAINDICATED WITH H/O
PEPTIC ULCER
28. PINDOLOL, ACEBUTOLOL, P
ENBUTOLOL
PARTIAL AGONISTS: β- BLOCKERS
WITH SOME INTRINSIC
SYMPATHOMIMETIC ACTIVITY
REDUCE VASCULAR
RESISTANCE
REDUCE CARDIAC OUTPUT OR
H.R LESS THAN OTHERS due to
agonist activity beneficial in cases of
bradyarrhythmias or PVD
29. LABETOLO, CARVEDILOL, NE
BIVOLOL
β- BLOCKING AND VASODILATING
ACTIVITY
LABETOLOL: 4 ISOMERS; 3:1 RATIO
OF β:α BLOCKADE
REDUCED SYSTEMIC VASCULAR
RESISTANCE(α-
BLOCKADE), COMBINED ACTIVITY
PHEOCROMOCYTOMA &
HYPERTENSIVE EMERGENCIES
30. CONT..
CARVEDILOL: HEART FAILURE
AND HYPERTENSION
NEBIVOLOL:
D- ISOMER: β-1 SELECTIVE
L-ISOMER: NITRIC OXIDE
SYNTHASE INDUCER PVR is
acutely lowered, has fewer side effects
31. ESMOLOL
β1- SELECTIVE BLOCKER
RAPIDLY METABOLISED BY RBC
ESTERASES
INDICATIONS: INTRA & POST
OP
HYPERTENSION, HYPERTENSIV
E EMERGENCIES PARTICULARLY
WHEN HYPERTENSION IS ASSOCATED
WITH TACHYCARDIA
32. PRAZOSIN & OTHER α1
BLOCKERS
SELECTIVE BLOCKAGE OF α1
RECEPTORS IN ARTERIOLES &
VENULES
LESS REFLEX TACHYCARDIA THAN
WITH NON SELECTIVE α BLOCKERS EG
PHENTOLAMINE
DLATION OF RESISTANCE &
CAPACITANCE VESSELS
B.P more in UPRIGHT position
More effective with β blockers & a diuretic
34. TOXICITY
FIRST DOSE SYNCOPE:
PRECIPITOUS DROP IN STANDING B.P
AFTER 1ST DOSE 1ST DOSE
ADMINISTERRED AT BEDTIME; Occurs in
salt & vol. depleted pts
DIZZINESS
PALPITATIONS
LASSITUDE
HEADACHE
+VE TEST FOR ANTI NUCLEAR
FACTOR BUT NO ASSOC. WITH R.A
37. HYDRALIZINE
RELEASE OF N2O
ARTERIOLAR DILATION
TACHYPHYLAXIS TO ANTI-HTN
EFFECTS DEVELOPED RAPIDLY
Low bioavailability ; first pass
metabolism by acetylation
38. TOXICITY
Headache
Nausea
Palpitation
Sweating
Flushing
Anorexia
May provoke ANGINA or ISCHEMIC
ARRHYTHMIAS
LUPUS-LIKE SYNDROME
arthralgia, myalgia, skin rashes, fever
Peripheral neuropathy and drug
fever…RARE
41. SODIUM NITROPRUSSIDE
INDICATIONS; HYPERTENSIVE
EMERGENCIES & HEART FAILURE
MOA: ACTIVATION OF GUANYLYL
CYCLASE( VIA N2O OR DIRECT) INC.
INTRA CELLULAR cGMP RELAXES
VASCULAR SMOOTH MUSCLE
ARTERIAL & VENODILATION
In pts with heart failure & low cardiac
output..output inc owing to afterload
reduction
42. DIAZOXIDE
EFFECTIVE & LONG ACTING
ARTERIOLAR DIATOR
RAPID FALL IN SYSTEMIC
VASCULAR RESISTANCE
OPENING OF POTASSIUM
CHANNELS
HYPOTENSION ACHIEVED WITH
SMALLER DOSES IN CHRONIC
RENAL FAILURE
Hypoglycemia secondary to
insulinoma
43. TOXICITY
CAN PROVOKE
ANGINA
ECG EVIDENCE OF ISCHEMIA
CARDIAC FAILURE,
In pts with ischemic heart disease
HYPERGLYCEMIA , particularly in pts
with RENAL INSUFFISIENCY